MYOCARDIAL SARCOMERE MECHANICS

心肌肌节力学

• 批准号: 2215174
• 负责人: GERALD H POLLACK
• 金额: $ 23.46万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2215174
• 关键词: Anura; biomechanics; heart contraction; ionic strengths; laboratory rabbit; laboratory rat; mechanical pressure; molecular pathology; muscle tension; myosins; sarcomeres

The aim of this research is to uncover the mechanisms underlying certain basic features of cardiac mechanics. To do so, we will carry out parallel experiments at each of three hierarchical levels of organization: isolated trabeculae, isolated single myofibrils, and isolated myofilaments. The first involves a preparation used in this laboratory for some time. Sarcomere mechanics of isolated cardiac trabeculae can be investigated with high spatial and temporal resolution. The second, single isolated myofibrils, is a preparation recently developed. It has the advantage that every sarcomere in the preparation can be observed, and since sarcomeres are in series, the tension generated by any given sarcomere is that measured at the end of the specimen. Thus, the mechanics of each sarcomere can be established unambiguously. The third preparation is the in vitro motility assay, in which the motion of fluorescently labelled actin filaments can be observed over a lawn of myosin heads planted on a substrate. By combining measurements of velocity and tension, mechanics of filaments can be established. By using these three preparations in parallel experiments, it will be possible to dissect mechanisms underlying basic features of mechanics. We plan to study length-tension relations, deactivation, tension-enhancement, effect of stretch, and other pertinent mechanical phenomena. By observing whether or not a phenomenon shows up at a certain level of structural organization, it will be possible to swiftly rule out certain putative mechanisms. We may then focus more intensely on others. The ability to explore mechanical phenomena at three levels of organization in the same laboratory should permit rapid advance in understanding of the basic principles of cardiac contraction.

这项研究的目的是揭示某些机制背后的机制 心脏力学的基本特征。 为此，我们将执行 三个层次中的每一个的平行实验 组织：分离的小梁、分离的单肌原纤维和 孤立的肌丝。 第一个涉及此中使用的制剂 实验室一段时间。 离体心脏的肌节力学 可以以高空间和时间分辨率研究小梁。 第二个，单个分离的肌原纤维，是最近准备的 发达。 它的优点是制备中的每个肌节 可以观察到，由于肌节是串联的，张力 任何给定的肌节产生的肌节是在肌节末端测量的 标本。 因此，可以建立每个肌节的力学 明确地。 第三个准备工作是体外运动测定， 荧光标记的肌动蛋白丝的运动可以是 在种植在基质上的肌球蛋白头草坪上观察。 经过 结合速度和张力的测量以及细丝的力学 可以成立。 并行使用这三种制剂 实验，将有可能剖析基本机制 力学的特点。 我们计划研究长度-张力关系， 失活、张力增强、拉伸效果和其他相关 机械现象。 通过观察某种现象是否出现 在一定的结构组织水平上， 迅速排除某些假定的机制。 然后我们可能会更加关注 强烈地关注他人。 探索机械现象的能力 同一实验室的三级组织应允许快速 加深对心脏收缩基本原理的理解。